alkanes! (and alkyl halides)

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Alkanes! (and alkyl halides). The Saturated Hydrocarbons . The Saturated HC’s-alkanes. Have only single bonds Also called the “paraffin compds” Paraffin is an older term meaning “of little activity” Alkanes are also saturated -meaning? Completely full of stuff Diaper demo. - PowerPoint PPT Presentation


  • Alkanes!(and alkyl halides)The Saturated Hydrocarbons

  • The Saturated HCs-alkanesHave only single bondsAlso called the paraffin compdsParaffin is an older term meaning of little activityAlkanes are also saturated-meaning?Completely full of stuffDiaper demo

  • Fossil FuelsThese are dead plants/animals that decay into a mixture of solid, liquid, and gaseous HCsNatural gas and petroleum are fossil fuels-usually found togetherWhat are they good for?Sources of NRG (fireplace story)Informative video with relaxing hypnotizing background music-10 min plastics, drugs, synthetic fibersPutting old tires in pavement video 1.3 min

    Asphalt RocketsTims movie here Aldin and Snoop Dog video making of the video

  • Fossil fuels contdCoalCoke-artificially made pure coalAnthracite-hard coal-purest in natureBituminous-contains sulfur (glove story)Lignite-brown coal, smoky flamePeat-partially decomposed organic matterDirty Jobs Video on coal mining 5 min maybe this ones better 5 min

  • Life-saving canaries

    Dont write all thisCoal mines are breeding grounds for methane and carbon monoxide, which are hazardous to human health, as well as conducive to deadly explosions. Before methane or carbon monoxide detectors existed, miners brought canaries down into coal mines with them. If a canary died, it was a sign of the presence of noxious gases and meant it was time to high tail it out of there.

  • Preparation of AlkanesExodus story*Israel has no oil!Alkanes are so abundant in nature that theres no need to make them in labInstead they are collected/purified for use

  • Petroleum Refining!Petroleum in its(*) natural state is worthlessIt can be made into useful products by refiningSee residueRefining videos 10 min

  • The 1st 10 alkanesrepresented by the formula CnH2n+2 See board Know the 1st 10 alkanes-name, molecular formula, and structural formula-also recognize expanded and condensed formsQ: Why are none of these alkanes solids?A: b/c they have very low freezing/melting pts-most are liquids or gasesQ: which is more gaseous-ethane or pentane?Bpts and mpts increase with # of Cs

  • N and Iso Alkanesalkanes that form a continuous unbranched chain are called normal or n-alkanesGive exsiso-alkanes have one branched C (on the second C) 4 kinds of carbonsPrimary, secondary, tertiary, quaternaryNormal alkanes have only primary and 2ndy CsIso-alkanes have at least one 3rd or 4th degree CEx: isopropyl acohol

  • Naming AlkanesIUPAC naming rules!Find longest continuous C chain, give it a base name (ex: propane, pentane)Identify side groups halogens-chloro, bromo, iodo, fluoroalkyl groups-methyl, ethyl, propylAssign prefixes, alphabetize, use lowest #sNaming cycloalkanes

  • Chemical Reactions of Alkanes


    General pattern for oxidation reactions is:

    HC + oxygen carbon dioxide + water + heat

    EX: methane + oxygencarbon dioxide + HOH

  • Exs of Combustion RxnsCH4 + 2O2 CO2 + 2H2O

    C3H8 + 5O2 3CO2 + 4H2O 2 min lady w/boring voice

  • The ratio of O to C is very imptW/out enough O2, you get CO instead of CO2Ex: car engineSo why would that be bad? 3 min video

  • What CO does in the bodyBlood loves CO 200x> than O2Blood exposed to CO is less able to pick up and distribute O2Symptoms of CO poisoning:HeadachesNauseaDeath 9 min

    CO poisoning storiesSkyline AcresProstitutes

  • The 2nd Chemical Rxn of Alkanes

    2. Substitution-sometimes you can sub a halogen for a hydrogen in an alkane making an alkyl halideEx rxn on boardAlkyl halides are very reactiveRepresented by "RX" (not "rxn")

  • Specific alkyl halides: Bromomethane or methyl bromideBerries from the west coast are made by forcing CH3Br into the soilground is covered w/plastic to keep gas from escaping, then crops are planted

    Huge berries are b/c CH3Br kills worms, fungi, dogs, cats, & Mexicans Mexicans?!

  • The govt plans to ban methyl bromideWhy?b/c its an ozone depletorMany crops depend on CH3BrIts also used in termite fumigation-houses covered in plastic-kills termites, rats, and vagrantsAlternatives to methyl bromide

  • ChloromethanesCH3Cl-chloromethane-a good liquid solvent

    CH2Cl2-dichloromethane-A good refrigerant

    CHCl3-trichloromethane (chloroform)Was once used in non-alcoholic pediatric cough syrupsCCl4-carbon tetrachlorideExcellent spot remover for dry cleaning, but carcinogenic, killed Chinese laundry workers

  • othersCF2Cl2 Dichlorodifluoromethane-FreonA refrigerant thats completely unreactiveHeat causes it to vaporize-goes into condenser, is liquified and reused.Olan storyIts also a good propellant b/c its unreactiveHow acs work- video

    Freon escapes into the stratosphere where its zapped w/UV light and removes Ozone (O3) O3 is like a screen that protects us from UV light-too much UV light can cause cancer

  • Chloroethane-see boardUsed as a cold spray to deaden skin before injectionsUsed by athletic trainers-deadens pain by cooling when players are hurtalso used to ripen fruitIn Israel, nanner trees are covered w/bags to help the nanners ripen faster